Carol Walker / Two wild Mustang stallions fighting in the White Mountain Herd Area, Wyoming, USA. August.

Carol Walker / Two white Camargue horses in ocean of Camargue, France, Europe. May.

Jeff Vanuga / White horses of the Camargue galloping through marshes in the Camargue, France. April.

Jeff Vanuga / White horses of the Camargue galloping through marshes in the Camargue, France. April.

Anup Shah / Burchell's Zebra (Equus burchellii) and Blue Wildebeest (Connochaetes taurinus) herd crossing river, Mara River, Masai Mara, Kenya

Jeff Vanuga / Grey Camargue horses, galloping through water in the Camargue, France, April.

Jeff Vanuga / Grey Camargue horses, galloping through water in the Camargue, France, April.

Kristel Richard / An equine trainer, in the traditional white Gujarati clothes, walks a Kathiawari horse mare on her hindlegs without strain, Porbandar, Gujarat, India, December 2012. No release available.

Carol Walker / Lusitano horse, grey stallion trotting, Portugal

Carol Walker / White horse of the Camargue, foal with its brown baby coat, Camargue, Southern France

Carol Walker / Two white horses of the Camargue, interacting, greeting head to head in marshes, Camargue, Southern France

Carol Walker / White horses of the Camargue with guardian, Camargue, Southern France. No release available.

Carol Walker / Two white horses of the Camargue, running through the sea, Camargue, Southern France

Carol Walker / White horses of the Camargue, herd running through water, Camargue, Southern France

Carol Walker / Two white horses of the Camargue, head to head at water, Camargue, Southern France

Konrad Wothe / Camargue horses (Equus caballus) running in water at beach, Camargue, France, April

Carol Walker / Mustang / wild horses, cremello colt foal Cremesso with grazing mare, McCullough Peak herd, Wyoming, USA, June 2007

Carol Walker / Mustang / wild horses, second year cremello colt Cremesso, reacting to black colt, McCullough Peak herd, Wyoming, USA, June 2009

Carol Walker / Mustang / wild horse, yearling cremello colt Claro in thick winter coat, stretching, McCullough Peak herd, Wyoming, USA, February 2008

Carol Walker / Mustang / wild horses, second year cremello colt Claro play fighting with bay, McCullough Peak herd, Wyoming, USA, July 2009

Carol Walker / Mustang / wild horses, two yearling cremello colts Claro and Cremesso playing with a bay, McCullough Peak herd, Wyoming, USA, June 2008

Carol Walker / Mustang / wild horse, cremello colt foal Cremesso interacting with yearling filly, McCullough Peak herd, Wyoming, USA, August 2007

Carol Walker / Claro and Cremesso, two third year male cremello Wild horse / mustang colts that had been rounded up from the McCullough Peak herd, Wyoming, and put up for adoption, on their new ranch in Colorado, US...

Carol Walker / Trainer Rich Scott with Cremosso, a young male cremello Wild horse / mustang that had been rounded up from a McCullough Peak herd and put up for adoption, trainer teaching it to be led in paddock, Jul...

Carol Walker / Wild Horse / Mustang shaking head and mane, Adobe Town Herd Area, southwestern Wyoming, USA, WINNER OF WILD HORSE SECTION, EQUINE IDEAL PHOTOGRAPHY CONTEST 2012

Kristel Richard / A purebred Lusitano stallion galloping in the arena at the Companhia das Lezírias Stud Farm, Samora Correia, Santarém, Portugal, July 2011

Carol Walker / Mustangs / wild horses, two cremello colts Claro and Cremosso interacting, mutual grooming, McCullough Peaks herd, Wyoming, USA, August 2007

Carol Walker / Spanish / Andalusian stallion performing Alta Escuela moves, rearing up, Andalucia, Spain

Kristel Richard / Close-up of the eye of a tobiano Kathiawari stallion, Gujarat, India.

Edwin Giesbers / Konik Wild Horse (Equus ferus caballus) in grasslands with Purple loosestrife flowers (Lythrum salicaria) in foreground. The Netherlands, July.

Kristel Richard / A Khampa warrior, mounted on his running Tibetan horse, tries to catch white scarves laid out on the ground, during the horse festival, near Huangyan, in the Garze Tibetan Autonomous Prefecture in the...

Aflo / ic-07106 Arab Horses galloping {Equus caballus}

Kristel Richard / A Shagya Arab stallion (Equus caballlus) is shown in hand in the courtyard of the Babolna Arabian Stud, Babolna, Komarom-Esztergom, Hungary.

Kristel Richard / Head portrait of a Classic pony stallion (Equus caballus) and one of his mares, in Auvergne, France.

Kristel Richard / Head portrait of a rare grey Yorkshire Dales gelding (Equus caballus) with long mane, at Glanusk Estate, Wales, UK

Kristel Richard / Close up of the curved ears of a rare Cremello Kathiawari mare with young Indian boy riding her, in Jasdan, Gujarat, India. The pink points on her head are tradionally put by women during ceremonies,...

Jean E. Roche / Close up of nostrils of White horse of the Camargue on wetlands, Camargue, France, January 2009

Wild Wonders of Europe / Hermansen / White horse, The Burren region, County Clare, Republic of Ireland, June 2009

Jeff Vanuga / Cowboys working for the Bureau of Land Management round up wild horses / mustangs to remove them from public land, Red Desert, Wyoming, USA. Model released

Wild Wonders of Europe / Allofs / White Camargue horse close-up of head, Camargue, France, May 2009

Wild Wonders of Europe / Allofs / White Camargue horse, mare with brown foal, Camargue, France, April 2009

Wild Wonders of Europe / Allofs / White Camargue horse portrait, Camargue, France, April 2009

Wild Wonders of Europe / Allofs / White Camargue horse stallion with a Cattle egret (Bulbulcus ibis) on his back, Camargue, France, April 2009

Wild Wonders of Europe / Allofs / White Camargue horse, mother with brown foal, Camargue, France, April 2009

Wild Wonders of Europe / Allofs / White Camargue horse, stallion in tall grass, Camargue, France, April 2009

Wild Wonders of Europe / Allofs / White Camargue horse grazing amongst Yellow flag irises, Camargue, France, April 2009

Carol Walker / Purebred Gypsy Vanner stallion running, Ojai, California, USA

Mitsuaki Iwago / Blue Wildebeest (Connochaetes taurinus) and Burchell's Zebra (Equus burchellii) herd migrating, Serengeti

Yva Momatiuk & John Eastcott / Burchell's Zebra (Equus burchellii) herd Blue Wildebeest (Connochaetes taurinus) and Thomson's Gazelles (Eudorcas thomsonii) congregate near crossing, Mara River, Masai Mara National Reserve, Kenya

Yva Momatiuk & John Eastcott / Burchell's Zebra (Equus burchellii) and Blue Wildebeest (Connochaetes taurinus) herds grazing together in open grassland during short rainy season in November, Masai Mara National Reserve, Kenya

Yva Momatiuk & John Eastcott / Burchell's Zebra (Equus burchellii) and Blue Wildebeest (Connochaetes taurinus) herds grazing together in open grassland during short rainy season in November, Masai Mara National Reserve, Kenya

Gerry Ellis / Burchell's Zebra (Equus burchellii) and Blue Wildebeest (Connochaetes taurinus) crossing the Mara River, Masai Mara National Reserve, Kenya

Mitsuaki Iwago / Blue Wildebeest (Connochaetes taurinus) herd with Burchell's Zebra (Equus burchellii) crossing river during migration, Serengeti

Mitsuaki Iwago / Blue Wildebeest (Connochaetes taurinus) herd with Burchell's Zebra (Equus burchellii) crossing river during migration, Serengeti

Ashley Cooper / Happisburgh on the Norfolk Coast. This section of coast is the fastest eroding point in the UK and speeding up due to global warming induced sea level rise and increased stormy weather. August 2006

Ashley Cooper / Happisburgh on the Norfolk Coast. This section of coast is the fastest eroding point in the UK and speeding up due to global warming induced sea level rise and increased stormy weather. August 2006

Ashley Cooper / Happisburgh on the Norfolk Coast. This section of coast is the fastest eroding point in the UK and speeding up to to global warming induced sea level rise and increased stormy weather. August 2006

Yva Momatiuk & John Eastcott / Icelandic Horse (Equus caballus), Hveravellir, Iceland

David Noton / Icelandic horses, one black and one white, near Helgafell, Snaefellsnes Peninsula, Iceland

Carol Walker / Head portrait of grey almost white Andalusian mare running in snow, Berthoud, Colorado, USA. January.

Carol Walker / Head portrait of grey Andalusian stallion running with mane flowing in arena in Northern France, Europe.

Carol Walker / Two wild Mustang stallions fighting in White Mountain Herd Area, Wyoming, USA. August.

Carol Walker / Wild Mustang stallion chasing another away from his family in White Mountain Herd Area, Wyoming, USA. August.

Carol Walker / Nine white Camargue horses running through water in Southern France, Europe. May.

Carol Walker / Two white Camargue horses swimming in ocean, Camargue, France, Europe. May.

Carol Walker / Two white Camargue horses running on beach in Camargue, France, Europe. May.

Carol Walker / Five white Camargue horses running through the water in Southern France, Europe. May.

Carol Walker / Thriteen white Camargue horses running through water in Southern France with flamingos in flight, Europe. May.

Carol Walker / Wild Mustang horses interacting, Pryor mountains, Montana, USA. June.

Benjamin Barthelemy / Two Camargue horses (Equus caballus), Camargue, France, May.

Jeff Vanuga / 'Guardian' cowboys moving the white horses of the Camargue, France, April 2015.

Jeff Vanuga / White horses of the Camargue in the marshes of the Camargue, France, April.

Jeff Vanuga / White horses of the Camargue galloping through marshes in the Camargue, France. April.

Constantinos Petrinos / One of the last two farriers on Spetses island kneels down in order to place shoeing horse, whilst farmer assists him by holding the horse's leg. No cars are allowed on the island, so horses are used...

Constantinos Petrinos / White horse standing next to white wall, Spetses island. No cars are allowed on the island, so horses are used to pull carriages. Spetses Island, Aegean Sea, Greece, Mediterranean, April 2009.

Constantinos Petrinos / Young boy and two white horses (Equus ferus caballus) traditional carriages used on Spetses Island to transport people as no cars are allowed on the island. Spetses Island, Aegean Sea, Greece, Mediter...

Kristel Richard / Two riders, dressed in Spanish period costume, ride two rare Kladruber horses/stallions (one black, one white), at the Great Riding festival, in Slatinany national stud, Pardubice Region, Czech Republ...

Kristel Richard / Two riders, dressed in Spanish period costume, ride two rare Kladruber horses/stallions (one black, one white), at the Great Riding festival, in Slatinany national stud, Pardubice Region, Czech Republ...

Richard Du Toit / Burchell's Zebra (Equus burchellii) stripes, Rietvlei Nature Reserve, South Africa

Nick Upton / English / Roman Chamomile (Chamaemelum nobile) flowering on heathland, with Horses (Equus caballus) grazing in the background, Corfe Common, Dorset, UK, July.

David Tipling / Greater flamingos (Phoenicopterus roseus) with Camargue white horses being herded behind. Camargue, France, February 2013.

Anup Shah / Blue Wildebeest (Connochaetes taurinus) and Burchell's Zebra (Equus burchellii) herd drinking in and crossing river, Mara River, Masai Mara, Kenya

Anup Shah / Burchell's Zebra (Equus burchellii) and Blue Wildebeest (Connochaetes taurinus) herd waiting to cross river, Mara River, Masai Mara, Kenya

Anup Shah / Blue Wildebeest (Connochaetes taurinus) and Burchell's Zebra (Equus burchellii) herd crossing river, Mara River, Masai Mara, Kenya

Anup Shah / Blue Wildebeest (Connochaetes taurinus) and Burchell's Zebra (Equus burchellii) herd crossing river, Mara River, Masai Mara, Kenya

Anup Shah / Blue Wildebeest (Connochaetes taurinus) and Burchell's Zebra (Equus burchellii) herd crossing river, Mara River, Masai Mara, Kenya

Anup Shah / Blue Wildebeest (Connochaetes taurinus) and Burchell's Zebra (Equus burchellii) herd watched by tourists in hot air balloons, Mara River, Masai Mara, Kenya

Anup Shah / Blue Wildebeest (Connochaetes taurinus) and Burchell's Zebra (Equus burchellii) herd watched by tourists in hot air balloons, Mara River, Masai Mara, Kenya

Markus Varesvuo / White-fronted Goose (Anser albifrons) flock flying over horses in field, Sweden, October 2004

Jean E. Roche / Camargue horses walking along path, Salin de Giraud, Camargue, France, September 2013.

Yva Momatiuk & John Eastcott / Domestic Horse (Equus caballus) in moorland, Isle of Skye, Scotland

Anup Shah / Burchell's Zebra (Equus burchellii) and Blue Wildebeest (Connochaetes taurinus) mixed herd running, Masai Mara National Reserve, Kenya

Anup Shah / Burchell's Zebra (Equus burchellii) in mixed herd with Blue Wildebeest (Connochaetes taurinus) crossing Mara River, Masai Mara National Reserve, Kenya

Anup Shah / Burchell's Zebra (Equus burchellii) in mixed herd with Blue Wildebeest (Connochaetes taurinus) crossing Mara River, Masai Mara National Reserve, Kenya